powerpc: P1011: Remove macro CONFIG_P1011

Replace CONFIG_P1011 with ARCH_P1011 in Kconfig. P1011RDB seems to be in
scrapyard though.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/Makefile b/arch/powerpc/cpu/mpc85xx/Makefile
index a663379..359ef0c 100644
--- a/arch/powerpc/cpu/mpc85xx/Makefile
+++ b/arch/powerpc/cpu/mpc85xx/Makefile
@@ -73,7 +73,7 @@
 obj-$(CONFIG_ARCH_MPC8569) += mpc8569_serdes.o
 obj-$(CONFIG_ARCH_MPC8572) += mpc8572_serdes.o
 obj-$(CONFIG_ARCH_P1010)	+= p1010_serdes.o
-obj-$(CONFIG_P1011)	+= p1021_serdes.o
+obj-$(CONFIG_ARCH_P1011)	+= p1021_serdes.o
 obj-$(CONFIG_P1012)	+= p1021_serdes.o
 obj-$(CONFIG_P1013)	+= p1022_serdes.o
 obj-$(CONFIG_P1014)	+= p1010_serdes.o